

/*
 * Copyright (c) 2011 Sapienza University of Rome.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the
 *   distribution.
 * - Neither the name of the Sapienza University of Rome nor the names of
 *   its contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SAPIENZA
 * UNIVERSITY OF ROME OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * This interface is provided by the NtpManagerC component which enables DISSense to be used with the bundled Java application "DISSense Manager".
 * Through this interface, the ManagerC component of DISSense is able to modify the schedule (wakeup time, sampling period) and synchronize to an external gateway.
 * This interface is also provided by the DummyNtpManagerC component which substitutes the NtpManagerC when the CFLAGS+=-DSINK string is commented in the Makefile.
 * @author Ugo Colesanti <colesanti@dis.uniroma1.it>
 * @version 1.01 (September 28, 2011)
 */

interface NtpSynchronization{
	
	/**
	 * Get the actual drift between the next wakeup scheduled by the ManagerC component of the Sink and the correct wakeup computed by the bundled Java application "DISSense Manager".
	 * @return The drift (in milliseconds) from the correct wakeup (or 0 if provided by the DummyNtpManagerC component)
	 */
	command uint32_t getNtpDrift() ;

	/**
	 * Get the drift from schedule
	 * @return The schedule drift
	 */

	/**
	 * Get the drift from a new schedule set from the external Java application "DISSense Manager". It allows the ManagerC component of DISSense to update its schedule.
	 * @return The drift (in milliseconds) from the new schedule (or 0 if now new schedule is submitted or if the interface is provided by the DummyNtpManagerC component)
	 */
	command uint32_t getScheduleDrift() ;

	/**
	 * Resets the values return by getNtpDrift() and getScheduleDrift(). It is required when an RI phase is scheduled in the ManagerC component of the Sink.
	 */
	command void resetFields() ;

}
